Nokia has announced that Henry Tirri will take up the role of chief technology officer (CTO), after his predecessor Richard Green took a 'leave of absence' in June.
On his departure, Nokia said that Green was leaving to attend to a "personal matter". He had only been CTO at Nokia since May 2010, and was the fourth CTO at the company in five years. As of today, Green has also left his position as member of the Nokia leadership team, which he joined on 11 February 2011.
"Green will be returning full-time to the US to pursue new opportunities," Nokia said in a statement.
Tirri was previously head of the Nokia Research Centre (NRC) and has been standing in for Green since he left. He joined Nokia in 2004 as a research fellow. He led NRC Systems Research laboratory in 2007.
Based in California, Tirri will report directly to Nokia president and CEO Stephen Elop.
"During his time at Nokia, Henry has provided Nokia technical leadership and challenged us to explore forward-looking technologies. In his new role, Henry will have the opportunity to make a greater impact and set the course for Nokia and our role in the mobile industry," said Elop.
Elop also thanked Green for his "key role" in "assisting Nokia through a major transition" and said.
In June, media reports claimed that Green left over strategic differences.
The BBC said that Green was a "champion" of the Linux-based MeeGo mobile operating system that Nokia abandoned for Microsoft's Window's Phone software.
The company had provided a stark profit warning due to plummeting sales of devices and services as it announced plans to move to a strategy of selling phones built around the Microsoft Windows Phone 7 operating system.